Professor Geoff Wild, University of Western Ontario
Location: Bourne Lecture Theatre 1
Why do individuals behave in ways that seem contrary to their own self-interest? One familiar answer to this question comes to us from kin-selection theory: selfless acts can be favoured by selection when they confer a sufficiently large benefit upon the actor’s genetic relatives. This familiar answer is often summarized by Hamilton’s rule, BR – C > 0, where C represents the additive fitness cost experienced by a selfless actor, and B represents an additive fitness benefit sent to a recipient, whose relatedness to the actor is described by R.
As Hamilton’s rule suggests, kin-selection theory (specifically, the notion of inclusive fitness) often neglects non-additive fitness consequences of behaviour. In other words, it typically sheds no light on the synergies that arise when the net effect of a social interaction exceeds the sum of its parts. This is a particular problem for those interested in studying many asymmetric contests in which opponents adopt distinct roles.
In the first part of my talk, I will focus on one such contest (the Ultimatum Game) and show how kin selection can be used to make useful qualitative predictions. I will also explain why I find the application of inclusive-fitness thinking (but not kin-selection thinking) to asymmetric contests, in general, rather awkward.
Moving on, I will provide a more optimistic view of the applicability of inclusive-fitness theory and kin selection. I will show that inclusive fitness, in particular, is a useful way to understand longer-term evolutionary outcomes related to asymmetric contests when those contests represent only one of many things that determine an individual’s fitness. I plan to illustrate this point by investigating long-term evolution of the cooperative strategies associated with an asymmetric version of well-studied social contests.
